
MC68HC16V1
MOTOROLA
MC68HC16V1TS/D
101
5.5.1 QSPI Pins
Seven pins are associated with the QSPI. When not needed for a QSPI function, they can be configured
as general-purpose I/O pins. The PCS0/SS pin can function as a peripheral chip-select output, slave
select input, or general-purpose I/O. Refer to Table 54 for QSPI input and output pins and their func-
tions.
5.5.2 QSPI Registers
The programming model for the QSPI submodule consists of the QSM global and pin control registers,
four QSPI control registers, one status register, and the 80-byte QSPI RAM.
The CPU can read and write to registers and RAM. The four control registers must be initialized before
the QSPI is enabled to ensure defined operation. SPCR1 should be written last because it contains
QSPI enable bit SPE. Asserting this bit starts the QSPI. The QSPI control registers are reset to a de-
fined state and can then be changed by the CPU. Reset values are shown below each register.
Table 55 shows a memory map of the QSPI.
Writing a different value into any control register except SPCR2 while the QSPI is enabled disrupts op-
eration. SPCR2 is buffered to prevent disruption of the current serial transfer. After completion of the
current serial transfer, the new SPCR2 values become effective.
Writing the same value into any control register except SPCR2 while the QSPI is enabled has no effect
on QSPI operation. Rewriting NEWQP[3:0] in SPCR2 causes execution to restart at the designated lo-
cation.
Table 54 QSPI Pins
Pin Name(s)
Mnemonic(s)
Mode
Function
Master In Slave Out
MISO
Master
Slave
Serial Data Input to QSPI
Serial Data Output from QSPI
Master Out Slave In
MOSI
Master
Slave
Serial Data Output from QSPI
Serial Data Input to QSPI
Serial Clock
SCK
Master
Slave
Clock Output from QSPI
Clock Input to QSPI
Peripheral Chip Selects
PCS[3:1]
Master
Select Peripherals
Peripheral Chip Select
Slave Select
PCS0
SS
Master
Slave
Selects Peripheral
Causes mode fault
Initiates Serial Transfer
Table 55 QSPI Memory Map
Address
Name
Usage
$YFFC18
SPCR0
QSPI Control Register 0
$YFFC1A
SPCR1
QSPI Control Register 1
$YFFC1C
SPCR2
QSPI Control Register 2
$YFFC1E
SPCR3
QSPI Control Register 3
$YFFC1F
SPSR
QSPI Status Register
$YFFD00
RR[0:F]
QSPI Receive Data (16 Words)
$YFFD20
TR[0:F]
QSPI Transmit Data (16 Words)
$YFFD40
CR[0:F]
QSPI Command Control (8 Words)